Abstract
Initiation of meiotic recombination by double-strand breaks (DSBs) must occur in a controlled fashion to avoid jeopardizing genome integrity. Here, we identify chromatin-associated protein HIM-17 as a link between chromatin state and DSB formation during C. elegans meiosis. Dependencies of several meiotic prophase events on HIM-17 parallel those seen for DSB-generating enzyme SPO-11: HIM-17 is essential for DSB formation but dispensable for homolog synapsis. Crossovers and chiasmata are eliminated in him-17 null mutants but are restored by artificially induced DSBs, indicating that all components required to convert DSBs into chiasmata are present. Unlike SPO-11, HIM-17 is also required for proper accumulation of histone H3 methylation at lysine 9 on meiotic prophase chromosomes. HIM-17 shares structural features with three proteins that interact genetically with LIN-35/Rb, a known component of chromatin-modifying complexes. Furthermore, DSB levels and incidence of chiasmata can be modulated by loss of LIN-35/Rb. These and other data suggest that chromatin state governs the timing of DSB competence.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, Non-P.H.S.
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Alleles
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Amino Acid Sequence
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Animals
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Caenorhabditis elegans
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Caenorhabditis elegans Proteins / chemistry*
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Caenorhabditis elegans Proteins / physiology*
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Cell Cycle Proteins / chemistry*
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Cell Cycle Proteins / physiology*
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Chromatin / metabolism*
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Chromosome Mapping
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DNA Methylation
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DNA-Binding Proteins / metabolism
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Endodeoxyribonucleases
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Esterases / metabolism
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Green Fluorescent Proteins
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Histones / metabolism
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In Situ Hybridization, Fluorescence
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Indoles
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Karyotyping
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Luminescent Proteins / metabolism
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Lysine / chemistry
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Meiosis*
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Models, Genetic
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Molecular Sequence Data
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Mutation
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Phenotype
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Prophase
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Protein Structure, Tertiary
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RNA Interference
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Rad51 Recombinase
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Recombination, Genetic*
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Sequence Homology, Amino Acid
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Time Factors
Substances
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Caenorhabditis elegans Proteins
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Cell Cycle Proteins
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Chromatin
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DNA-Binding Proteins
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HIM-17 protein, C elegans
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Histones
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Indoles
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Luminescent Proteins
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Green Fluorescent Proteins
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DAPI
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Rad51 Recombinase
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rad-51 protein, C elegans
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Endodeoxyribonucleases
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Esterases
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meiotic recombination protein SPO11
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Lysine